Disease, advancing age, and trauma can lead to changes in various bones, discs, joints, and ligaments of the body. Some changes and trauma often manifest themselves in the form of damage or degeneration to a spinal disc. This condition often results in chronic back pain, which can be anywhere from mild to severe. This pain can sometimes be eliminated by spinal fusion in which two adjacent vertebral bodies are jointed together after removing the intervening intervertebral disc. A prosthetic device is usually placed between the two adjacent vertebral bodies, in place of the removed disc, to fill the space left by the removed disc and to allow bone to grow between the two vertebral bodies.
More recently, spinal disc replacement implants have been developed that allow motion between the adjacent vertebrae, thereby restoring normal function to the vertebrae. These implants generally rely on spherical, cylindrical, or otherwise shaped bearing surfaces to allow movement between two components. While many of the current designs are successful, some of the challenges with current designs include wear levels, fatigue under loading, range of motion, and surgical window size required to implant the disc replacement.
Accordingly, there remains a need for improved methods and devices for replacing a spinal disc.